It's me again! Been a while, I've been pretty content with how the bikes been running. However, I find myself unable to cruise at any speed above 3rd gear(even wot in 6th) still think it's the carbs. Now keep in mind I did check clutch basket an had to replace the part the springs hold in (drawing a blank) after that ran great ,no slipping an shifting got better. Even still if I wanna cruise at 45mph in 4th it's like the bike isn't getting power (surging slightly) shift down into 3rd an I can hold speed but high in the gear. If it were carbs wouldn't I have issue in all gears?? And could it be possible that it's not firing correctly? I have spark on all 4 (bright blue) p.s. only gets bad after a decent ride of an hour or more.
TIA any help is helpful

 

Air box isn't sealed completely, aaand coils were not secure lol. Vibration is more than a buzz but not terrible. Plus needs neck bearings, so that adds more vibration. It's time for a new bike but we all know how that goes. Maybe when I grow up lol